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Archiver > DNA-R1B1C7 > 2011-06 > 1309169910


From: "Sandy Paterson" <>
Subject: [R-M222] O'Cathain, off modal matches, 448=16
Date: Mon, 27 Jun 2011 11:18:30 +0100


Two Points here. Firstly, Ken Nordtvedt's paper at

http://www.jogg.info/42/files/Nordtvedt.htm


is relevant. Essentially, he explains that matches that appear to be close,
are actually about twice as distant as traditional TMRCA estimation suggests
they are. Further, traditional methods of estimation exaggerate the TMRCA
for more distant matches. I couldn't find what he means by traditional
methods, but I did manage to follow most of his reasoning.

So we may be seeing a little of that here.

Secondly, (as you know), rare matches are more important than common matches
(as you've pointed out with DYS448). So the more off-modal (rare) matches
you have with someone, the lower the expected TMRCA for a given GD.

In our case, we have six off-modal matches, at

DYS439=13
DYS570=18
DYS710=34
DYS715=23
DYS513=14
DYS643=11

In addition, we have what I've come to term a 'directional match', in that
we are both 14+ at DYS=446 (modal value 13). I am 15, you are 14.

I think it's going to be interesting seeing whether the 23,14,11 at
DYS715,513,643 is present in Cain and variants with DYS446=13. If not, that
will give us a useful clue as to kinship. If it is present, that knowledge
should help in trying to work out the order in which the mutations most
likely occurred.


Sandy


-----Original Message-----
From:
[mailto:] On Behalf Of Charles Cain
Sent: 26 June 2011 19:25
To:
Subject: [R-M222] O'Cathain, off modal matches, 448=16

Looking at Sandy's chart, I am struck by how "unrelated" in GD terms
we all are although that is a relative concept I suppose. Under each
new name on the chart, the most closely related subject almost always
jumps to a GD of over 10 with around 15 being the most common (too
lazy to compute the average "jump"). The value of off-modal markers
becomes obvious from this chart.

In my own case, the jump in GD is only 4 to a Kane. We have compared
notes because I noticed several years ago the we share an off-modal
match at marker 448. In M222 this marker is uniformly 18 repeats.
However, 4 "Cain/Kanes" have 448=16, extremely rare and not shared (to
my knowledge) by anyone else.

In contacting these people, one 25 marker Cain (GD=0), turned out to
be related on paper back to a common ancestor just before 1800. If
fact, the father of this common ancestor was at Valley Forge in the
Revolutionary War, always an interesting fact to turn up. Also, his (
Mr. Valley Forge's) father was the likely immigrant from Ireland to
New Jersey in 1740. So DNA helps!

Another 448=16 colleague (the other Kane/Cain with 111 marker results)
is unlikely to be related before the 1740 date mentioned above. This
is based on lack of common spelling of our last name, different family
religious affiliations, and different arrival times of our immigrant
ancestors. So we are related only before 1740.

On one of the DNA tree charts (I think based on Bill Howard's
computations), we reach a common branch at about RCC=9, or some 400
years ago, or around 1600. This is entirely consistent with what is
likely true from other considerations.

Moreover, both of us (Cain and Kane) trace back to the next branching
of the "RCC tree" at around RCC=22, or some 950 years. If Bill
Howard's computations are sensitive to rarity of mutations at each
site, that is a good guess for when the 448 =16 mutation (from 448=18)
occurred. If true, I am related to no other O'Cathain with 448=18
after the year AD 1000. That seems like a useful piece of data.

In that regard, if you want to know who to contact regarding possible
common ancestors, look at rare off-modal matches. I has worked for my
448=16 colleagues and myself.

Bill Howard may want to comment on my use of his data in the above
exercise...particularly my use of his data to "estimate" when the
448=16 mutation occurred.

Charles




R1b1c7 Research and Links:

http://clanmaclochlainn.com/R1b1c7/
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